Button not working Android Wear Custom Cards

Question

I'm trying to create a custom card in android wear app (this card is created by WearableListenerService),my problem is when the card appears and my application is closed the button on the card does not work, but when the application is running the button works well. I stated to develop to android recently and I 'm not getting fix the problem , someone could help me ? Thank you very much

1. Service

 public class ListenerService extends WearableListenerService {
    private static final String _MESSAGE_PATH = "/message_path";

    private static final String _NOTIFICATION_NUMBER = "/notificationNumber";

    private static Context _context;

    public void onMessageReceived(MessageEvent messageEvent) {

        switch(messageEvent.getPath()){
            case _MESSAGE_PATH:
                break;

            case _NOTIFICATION_NUMBER:
                _context = getBaseContext();
                new Thread(tCards).start();
                break;
            default:
                super.onMessageReceived(messageEvent);
                break;
        }
    }

    private Runnable tCards = new Runnable(){
        public void run() {
            Intent _Card = new Intent();
            _Card.setClass(map, CardCall.class);
            _Card.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            _context.startActivity(_Card);
        }
    };
}

2. CardClass

public class CardCall extends Activity {

    ClientAction client = ClientAction.getInstance();
    BoxInsetLayout _boxBK;
    ImageButton imgCancel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.cards_main);

        CardScrollView cardScrollView =
                (CardScrollView) findViewById(R.id.card_scroll_view);
        cardScrollView.setCardGravity(Gravity.BOTTOM);

        imgCancel = (ImageButton) findViewById(R.id.btnStopSong);
        _boxBK = (BoxInsetLayout) findViewById(R.id.background);
        _boxBK.setBackgroundColor(Color.BLUE);

        imgCancel.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new TaskStop().execute();
            }
        });
    }

    private class TaskStop extends AsyncTask<Void, Void, Void>
    {
        @Override
        protected void onPreExecute() {
            super.onPreExecute();

        }

        @Override
        protected Void doInBackground(Void... params) {
            client.StopSong("");
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);

        }
    }
}

3. Card Layout

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.wearable.view.BoxInsetLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/background"
        android:layout_height="match_parent"
        android:layout_width="match_parent">

        <android.support.wearable.view.CardScrollView
            android:id="@+id/card_scroll_view"
            android:layout_height="match_parent"
            android:layout_width="match_parent"
            app:layout_box="bottom">

            <android.support.wearable.view.CardFrame
                android:layout_height="wrap_content"
                android:layout_width="fill_parent">

                <LinearLayout
                    android:layout_height="wrap_content"
                    android:layout_width="match_parent"
                    android:orientation="vertical"
                    android:paddingLeft="5dp">

                    <TextView
                        android:fontFamily="sans-serif-light"
                        android:layout_height="wrap_content"
                        android:layout_width="100dp"
                        android:text="Text titulo"
                        android:textColor="@color/black"
                        android:textSize="20sp"/>
                    <TextView
                        android:fontFamily="sans-serif-light"
                        android:layout_height="wrap_content"
                        android:text="textDescricao"
                        android:textColor="@color/black"
                        android:layout_width="100dp"
                        android:textSize="14sp"/>


                    <ImageButton
                        android:layout_width="50dp"
                        android:layout_height="50dp"
                        android:id="@+id/btnStopSong"
                        android:src="@drawable/ic_end_white_36dp"
                        android:background="@drawable/button_round"
                        android:layout_gravity="bottom" />

                </LinearLayout>
            </android.support.wearable.view.CardFrame>
        </android.support.wearable.view.CardScrollView>
    </android.support.wearable.view.BoxInsetLayout>

</RelativeLayout>